The dendritic cell (DC) maturation process is essential for the development of T cell responses and immune tolerance. Accordingly, DCs are considered a major target in the development of immunomodulating agents. In the present study, the effect of sinulariolide, an active compound isolated from the cultured soft coral Sinularia flexibilis, on lipopolysaccharide (LPS)‑induced murine bone marrow‑derived DCs was evaluated. The different phenotypes, cytokine secretion and the mix‑lymphocyte reaction of DCs were detected using flow cytometry and ELISA. The experimental results revealed that the phenotypic and functional maturation of DCs stimulated by LPS were markedly reduced by sinulariolide in a concentration‑dependent manner, including the expression of co‑stimulatory molecules (CD40, CD80 and CD86). In addition, sinulariolide reduced the release of tumor necrosis factor‑α, interleukin (IL)‑6, IL‑12 and nitric oxide from the LPS‑activated DCs, decreased their abilities to stimulate allogeneic T cell proliferation, and inhibited LPS‑induced nuclear factor‑κB pathways. These findings offer novel insight into the immunopharmacological function of sinulariolide and its effects on DCs.

Background: Kan-Lu-Hsiao-Tu-Tan (KLHTT) exhibits anti-psoriatic effects through anti-inflammatory activity in mice. However, the therapeutic effects of KLHTT on rheumatoid arthritis (RA), another significant autoimmune inflammatory disorder, are not elucidated. Herein, we explored the anti-arthritic effects of KLHTT on collagen-induced arthritis (CIA) in mice. Methods: KLHTT was extracted by boiling water and subjected to spectroscopic analysis. Chicken collagen type II (CII) with complete Freund’s adjuvant was intradermally injected to induce CIA in DBA/1J mice. Anti-CII antibody, cytokines, malondialdehyde (MDA), and hydrogen peroxide (H2O2) were measured using ELISA, thiobarbituric acid reactive substances, and hydrogen peroxide assay kit. Splenocyte proliferation was tested using thymidine incorporation. Th1 and Th17 cells were analyzed by flow cytometry. Results: Oral KLHTT treatment (50 and 100 mg/kg) ameliorated mouse CIA by decreasing the levels of interleukin (IL)-1β, IL-6, IL-17A, and tumour necrosis factor-α in the paw homogenates and serum. KLHTT also suppressed anti-CII antibody formation, splenocyte proliferation, and splenic Th1 and Th17 cell numbers. Additionally, KLHTT showed antioxidant activity by reducing the concentrations of MDA and H2O2 in paw tissues. Conclusions: The therapeutic effects of KLHTT in CIA mice were through regulating oxidative stress and inflammatory responses. Our results suggest that KLHTT has potential to treat RA.

Background Rheumatoid arthritis (RA) is an autoimmune disease featured by joint inflammation and systemic comorbidities. Kan-Lu-Hsiao-Tu-Tan (KLHTT), a Chinese medicine formulation, has free radical scavenging capacity and anti-inflammatory activity in vitro. However, its anti-arthritic effect remains unknown. Herein, we aimed to explore the anti-arthritic effects of KLHTT on collagen-induced arthritis (CIA) in mice and investigate the underlying mechanisms. Methods KLHTT was extracted using boiling water. KLHTT (50 and 100 mg/kg) was fed orally for 21 days once a day on CIA in DBA/1J mice. The severity of CIA was evaluated by histological assessments. Levels of inflammatory cytokines, malondialdehyde (MDA), and hydrogen peroxide (H2O2) were measured using ELISA, thiobarbituric acid reactive substances, and hydrogen peroxide assay kits, respectively. Anti-collagen type II (CII) antibody was assayed by ELISA. Proliferation of splenocytes was tested using radioactive thymidine incorporation assay. Levels of Th1 and Th17 cells were obtained using flow cytometry. Results KLHTT significantly ameliorated paw edema and restored body weight in CIA mice. The synovitis, cartilage damage, and bone erosion were reduced by KLHTT. KLHTT exhibited anti-inflammatory effects by decreasing the levels of interleukin (IL)-1β, IL-6, IL-17A, and tumour necrosis factor-α in the paw homogenates and serum. KLHTT also showed antioxidant activity by reducing the concentrations of MDA and H2O2 in paw tissues. Moreover, KLHTT reduced anti-CII antibody formation, suppressed splenocyte proliferation, and mitigated the levels of splenic Th1 and Th17 cells in CIA mice. Conclusion The therapeutic effects of KLHTT in CIA mice were through regulating immune and inflammatory responses. Our results suggest that KLHTT has potential to treat rheumatoid arthritis.